Biomedical subjects

F G Sander

Publications and source records attributed to F G Sander.

At least 19 recordsLinked to original sources

PubMed1991

[3-dimensional computer-supported model and hologram evaluations].

For the three-dimensional measurement of plaster casts and holograms a self-fabricated measurement device will be introduced. This measurement device has the following specialties: 1. All measurements will be done without any subsidiary optical instruments like spectacles, microscope, binoculars or any thing else. Therefore a tire of measuring can be carried out. 2. Only two 3 mm deep holes should be ground in the base of the plaster casts as preparatory measures for the three-dimensional measurements of the plaster casts. 3. The menu- and window-orientated software gives the possibility for the collecting of data in a data bank. 4. The precision of these measurement results, even in the case of measuring holograms, are frequently better than the common way of measuring plaster casts. 5. The precision and information by the holograms are nearly the same, compared with the common plaster casts. 6. The tracing and measuring of the angles and lines by this newly measurement device guarantees the doctor a quick overview concerning the therapeutic measures. 7. The transfer of these data in the lateral-rays and in the posterior-anterior findings leads to a better diagnostic. That means the diagnostic horizon will be widened with this new method.

Computer Simulation↗

PubMed1991

[Biomechanical aspects of the spring-active-appliance during the night sleep].

1. During the night the mandibular activities caused by the spring-active-appliance are increased. Seven times more mandibular movements occur compared to the activator according to Andresen-Häupl. 2. A distinct increased mandibular activity during the time the patient fall asleep or in the wake up time can be registered, especially in the adaptation phase or after reactivating the springs. 3. Powerful activities of the m. masseter did not lead to an inversion of the mandibular movement. 4. A regular movement of the mandible is the most frequent movement whilst mandibular activities. 5. During the night asymmetrical activities of the mm. masseters very often occur. 6. An inversion of the mandibular movement, that means a counter-clockwise-rotation of the m. mandible, occurs if the force direction of the m. temporalis is directed more distally or if the ratio between masseter- and temporalis activities are for the benefit of the temporalis-activities. 7. During the night the springs in the spring-active-appliance cause a counter-clock wise-rotation of the mandible without mandibular activities around a transverse axis in the region of the molars. This leads to an approach of the anterior teeth whilst the distance between the molars remains constant. 8. Contrary movements and rotations around a transverse axis in the region of the molars lead to a distraction of the condyle of about one millimeter.

Activator Appliances↗

PubMed1991

[The bite-jumping-appliance].

By the development of the bite-jumping-appliance (BJA) the wearing comfort for the patient was significantly improved and also the handling through the doctor was multiple facilitated. 1. While treating with the BJA the forward advancement of the mandible can be done simultaneously with the harmonizing of the maxillary and mandibular dental arches. 2. The wearing comfort during the day time, as well as the speech with the BJA in the patients mouth is possible without any problems due to the fact, that the BJA consist of two separate appliances. 3. The functioning of the BJA can be improved while using extraoral forces. Also the wearing of the BJA without extraoral forces leads to a headgear effect onto the maxilla. 4. Also uncontrolled muscle activities during the night leads, if the muscle activity is great enough, to a total biting together. 5. To avoid the contact between protrusive sticks and inclined plane in the lower appliance, the patient will bring unconsciously the mandible, while speaking during day time, in a more anterior position. This training effect leads to an accelerated forward advancement of the mandible as well as to an accelerated harmonizing of the muscular chewing pattern in the anterior position. 6. A harmonized muscular chewing pattern in the sagittal plane as well as in the frontal plane can be achieved in nearly all patients after finishing the BJA-therapy. These results couldn't be achieved with other bimaxillary appliances [28].

Activator Appliances↗

PubMed1990

[The modification of growth with the jumping-the-bite plate compared to other functional orthodontic appliances].

The bite-jumping-appliance BJA is a special functional appliance which affects the upper jaw comparably to activator headgear combinations (SNA angle). Concerning its influence on the lower jaw (SNB angle) the BJA can be compared with the Teuscher activator and the Klammt activator. The change in the inclination of the upper jaw (ANS-PNS to nasion-sella) proved to be negligible because the vector of the force passed through the center of resistance of the upper jaw. The extend of the dental influence was the largest with the activator, the smallest with the Fränkel II appliance. The inclination of the lower incisors (1 to gonion-menton) was hardly affected. The upper incisors were retruded however not be the same extend as with the Teuscher activator which even has torque springs (to avoid the retrusion). The treatment of all the patients ended in all cases excepting those that were treated with an activator in a nearly ideal IIW angle. Our findings encourage us to say that the BJA is an appliance with a far better working mechanism than the working mechanism of other functional appliances.

Activator Appliances↗

PubMed1990

[Biomechanic of the asymmetrical headgear].

The asymmetrical headgear is a very useful treatment device for the unilateral distalisation of molars or for the correction of an unilateral anchorage loss. 1. The dimension of the asymmetrical effect depends on the configuration of the outer bows. 2. The function of an asymmetrical face-bow can be increased or decreased by eccentric bendings. 3. According to the geometry at the outer-bows the force at the outer-bow is divided at a different percentage onto the molars. 4. While the forces increase the asymmetrical effect will decrease when the outer-bow is too flexible. 5. Attention has to be payed at each control-appointment to the distance of the longer outer-bow to the cheek. 6. The asymmetrical swivel face-bow did not produce a greater asymmetrical function than other asymmetrical headgears. The reason of this fact is, that only the geometry of the outer-bows is responsible for the unilateral distalisation. 7. The asymmetrical swivel face-bow as described above is advisable to use because eccentric bendings and less forces at the outer-bows will decrease, stop or even reverse the asymmetrical effect. 8. The side-effect of any asymmetrical face-bow is a lateral force-component. This force-component can cause a cross-bite at the molar which has to be more distalized. The molar which is not be moved by the asymmetrical face-bow will be moved buccally by this force-component. 9. The swivel face-bow according to Sander prevents the buccal movement of the molar which should not be moved. But the tendency to create a cross-bite for the molar which should be more distalized, increases. 10. The swivel face-bow according to Sander can be combined with all well-known extraoral tractions. 11. Equal forces at the outer-bows can be reached while using a cervical-pull neckstrap according to Sander. 12. The asymmetrical face-bow and the bite-jumping-appliance can be used simultaneously if the face-bow inserts directly into the attachments of the molar bands.

Adolescent↗

PubMed1990

[Tooth mobility following treatment with removable appliances].

After a therapy with removable appliances all the teeth showed an increased loosening degree, that means tooth mobility, in comparison to an untreated control group. All the measured patients had been in the retention phase after an average treatment time of 4 years in cases of male patients and 3.8 years in cases of female patients.

Diagnosis, Oral↗

PubMed1990